Differential expression of two winter wheat alpha-tubulin genes during cold acclimation.

Overwintering crops, such as winter wheat, display significant increase in freezing tolerance during a period of cold acclimation (CA). To gain better understanding of molecular mechanisms of CA, it is important to unravel functions and regulations of CA-associated genes. Differential screening of a cDNA library constructed from cold-acclimated crown tissue of winter wheat identified an alpha-tubulin cDNA clone named wca18g11 that showed elevated expression upon cold acclimation. Nucleotide sequence analysis showed that the clone encoded a group 3 alpha-tubulin. Reverse transcription real-time PCR analysis of the expression of both wca18g11 clone and its closest paralogs of the wheat tubulin A-2 homeologous group during the course of cold acclimation revealed that both genes were differentially regulated with distinct expression patterns. The involvement of the two alpha-tubulin genes in cold acclimation and signal transduction is discussed.